In vitro manipulation of nucleic acids and proteins is an important aspect of modern molecular biology and functional genomics. Recent advances in DNA synthesis have started to make the production of large scale DNA libraries an economical reality. However, the next step, the use of those DNA libraries to produce large ordered protein libraries has not scaled to the same extent. Synthetic DNA constructs encoding genes are routinely cloned into plasmids that are then introduced into bacteria which are then in turn, used as hosts for protein production. While these techniques themselves are routine, they are time consuming and relatively limited in the potential scale of the library to be generated. As for commercially available libraries, each component of the library must be grown up in the host bacteria separately. This limits the scalability of in vivo protein library expression as each sample must be grown up in a minimal volume in order to produce enough protein to work with in downstream applications. In addition, growth of the host bacteria can be costly in time, taking a day or more of time for incubation. Together, these issues limit the number of samples that can be effectively grown in parallel.
Accordingly, there is a need for high-throughput techniques for the rapid synthesis and selection of genes and proteins of interest. Such techniques would permit the discovery and development of proteins with improved properties that can be used for analytical, research, diagnostic, and therapeutic purposes.